More than “just a drop”: the enigmatic role of liquid additives in mechanochemistry

We debate the role of liquid additives in liquid-assisted mechanochemistry, highlighting how miniscule amounts of liquid profoundly and mostly inexplicably affect the mechanism and outcomes of mechanochemical reactions. A critical analysis of well-known mechanochemistry studies, along with those reporting emerging concepts (such as the competitive liquid effect and dual-function liquids) underpins the complexity and mystery surrounding mechanochemical processes and suggest where the most series gaps in our understanding of mechanochemistry lie.